sigma-rules/rules_building_block/execution_mcp_server_child_process.toml

[metadata]
creation_date = "2025/12/04"
integration = ["endpoint", "windows", "sentinel_one_cloud_funnel", "m365_defender"]
maturity = "production"
updated_date = "2026/04/21"

[rule]
author = ["Elastic"]
building_block_type = "default"
description = """
Detects child process execution from GenAI tools or MCP (Model Context Protocol) servers. Adversaries exploit AI agents
to execute system commands, exfiltrate data, or establish persistence. MCP servers provide LLMs direct access to execute
shell commands, read files, and interact with external services. This building block provides visibility into
AI-initiated process execution for correlation with other suspicious activity.
"""
from = "now-119m"
index = [
    "logs-endpoint.events.process-*",
    "logs-windows.sysmon_operational-*",
    "logs-m365_defender.event-*",
    "logs-sentinel_one_cloud_funnel.*",
]
interval = "60m"
language = "eql"
license = "Elastic License v2"
name = "GenAI or MCP Server Child Process Execution"
risk_score = 21
rule_id = "b2c3d4e5-f6a7-8901-bcde-f23456789012"
severity = "low"
tags = [
    "Domain: Endpoint",
    "OS: Linux",
    "OS: macOS",
    "OS: Windows",
    "Use Case: Threat Detection",
    "Tactic: Execution",
    "Data Source: Elastic Defend",
    "Data Source: Sysmon",
    "Data Source: Microsoft Defender XDR",
    "Data Source: SentinelOne",
    "Rule Type: BBR",
    "Domain: LLM",
    "Mitre Atlas: T0053",
]
timestamp_override = "event.ingested"
type = "eql"

query = '''
process where event.type == "start" 
  and (
    // GenAI clients
    process.parent.name in (
      "Cursor", "Cursor.exe", "cursor",
      "Cursor Helper", "Cursor Helper (Plugin)", "Cursor Helper (GPU)", "Cursor Helper (Renderer)",
      "Claude", "Claude.exe", "claude",
      "Claude Helper", "Claude Helper (Plugin)", "Claude Helper (GPU)", "Claude Helper (Renderer)",
      "Windsurf", "Windsurf.exe", "windsurf",
      "Windsurf Helper", "Windsurf Helper (Plugin)", "Windsurf Helper (GPU)", "Windsurf Helper (Renderer)",
      "Code", "Code.exe", "code",
      "Code Helper", "Code Helper (Plugin)", "Code Helper (GPU)", "Code Helper (Renderer)",
      "codex", "codex.exe",
      "Copilot", "Copilot.exe", "copilot",
      "Jan", "Jan.exe", "jan",
      "Jan Helper", "Jan Helper (Plugin)", "Jan Helper (GPU)", "Jan Helper (Renderer)",
      "LM Studio", "LM Studio.exe", "lmstudio",
      "Ollama", "Ollama.exe", "ollama",
      "GPT4All", "gpt4all", "gpt4all.exe",
      "textgen.exe", "textgen", "text-generation-webui.exe", "oobabooga.exe",
      "gemini-cli.exe", "gemini-cli",
      "genaiscript.exe", "genaiscript",
      "grok.exe", "grok",
      "qwen.exe", "qwen",
      "koboldcpp.exe", "koboldcpp", "KoboldCpp",
      "llama-server", "llama-cli",
      "OpenClaw", "openclaw", "openclaw.exe",
      "Moltbot", "moltbot", "moltbot.exe",
      "Clawdbot", "clawdbot", "clawdbot.exe"
    ) or
    // OpenClaw/Moltbot/Clawdbot via Node.js
    (process.parent.name in ("node", "node.exe") and
     process.parent.command_line like~ ("*openclaw*", "*moltbot*", "*clawdbot*")) or
    // Package managers running MCP servers
    (process.parent.name in ("npx", "npx.exe", "pnpm", "pnpm.exe", "yarn", "yarn.exe", "bunx", "bunx.exe") and
     process.parent.command_line like~ ("*@modelcontextprotocol/*", "*mcp-server-*", "*mcp_server*")) or
    
    // Node/Deno/Bun running MCP servers
    (process.parent.name in ("node", "node.exe", "deno", "deno.exe", "bun", "bun.exe") and
     process.parent.command_line like~ ("*@modelcontextprotocol/*", "*mcp-server-*", "*mcp_server*")) or
    
    // Python MCP servers
    (process.parent.name like~ "python*" and
     process.parent.command_line like~ ("*-m mcp_server*", "*mcp-server-*", "*mcp_server*")) or
    
    // MCP server binaries
    process.parent.name like~ ("mcp-server*", "*-mcp-server", "*_mcp_server*") or
    process.parent.name in ("mcp-server", "mcp-server-elastic-cloud", "github-mcp-server")
  )
  and process.name != null
  // Exclusions
  and not (
    // Runtime self-spawns
    (process.parent.name in ("node", "node.exe") and process.name in ("node", "node.exe")) or
    (process.parent.name like~ "python*" and process.name like~ "python*") or
    (process.parent.name in ("deno", "deno.exe") and process.name in ("deno", "deno.exe")) or
    (process.parent.name in ("bun", "bun.exe") and process.name in ("bun", "bun.exe")) or
    
    // Helper process self-spawns
    (process.parent.name == "Cursor" and process.name like~ "Cursor Helper*") or
    (process.parent.name == "Claude" and process.name like~ "Claude Helper*") or
    (process.parent.name == "Windsurf" and process.name like~ "Windsurf Helper*") or
    (process.parent.name == "Code" and process.name like~ "Code Helper*") or
    (process.parent.name == "Jan" and process.name like~ "Jan Helper*") or
    (process.parent.name == "LM Studio" and process.name like~ "LM Studio Helper*") or
    (process.parent.name == "Ollama" and process.name like~ "Ollama Helper*") or
    
    // docker
    (process.name in ("docker", "docker.exe") and process.args == "context" and process.args == "ls") or
    // neighbor / arp / ps / which (args tokens or full /bin/sh -c)
    (
      process.args in (
        "ip neigh show",
        "arp -a -n -l",
        "ip neighbor show dev wlan0",
        "ip neighbor show dev eth0",
        "arp -a | findstr /C:---"
      ) or
      process.command_line in (
        "/bin/sh -c ip neigh show",
        "/bin/sh -c arp -a -n -l",
        "/bin/sh -c /bin/ps -ax -o pid=,ppid=,pcpu=,pmem=,command=",
        "/bin/sh -c which ps"
      )
    ) or
    // git
    (process.name in ("git", "git.exe") and (
      (process.args == "remote" and process.args == "get-url" and process.args == "origin") or
      (process.args == "symbolic-ref" and process.args == "refs/remotes/origin/HEAD" and process.args == "--short") or
      (process.args == "rev-parse" and process.args == "--abbrev-ref" and process.args == "HEAD") or
      (process.args == "status" and process.args == "-z" and process.args == "-uall") or
      (process.args == "config" and process.args == "--get" and process.args == "commit.template") or
      (process.args == "config" and process.args == "user.email") or
      (process.args == "rev-parse" and process.args == "--show-toplevel")
    )) or
    // version / help
    process.args in ("--version", "--help", "-v", "-h", "-V", "version", "help")
  )
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"


[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"